1. Field of the Invention
The present invention relates to an easy-to-operate and easy-to-assemble ratcheting-type wrench.
2. Description of the Related Art
Several factors are considered in designing wrenches and spanners, including improving the torque-bearing capacity, providing as many teeth as possible for the drive member, and providing an easy-to-manufacture structure. FIG. 14 of the drawings illustrates a conventional wrench of the type having a handle Bxe2x80x2 and a head in which a drive member Axe2x80x2 is rotatably received. A pawl Dxe2x80x2 is slidably received in a transverse through-hole Cxe2x80x2 in a web between the handle Bxe2x80x2 and the head. However, an end of the pawl Dxe2x80x2 extends beyond the transverse through-hole Cxe2x80x2 and thus adversely affects operation of the wrench when used in a limited space. A two-pawl type wrench was proposed to solve this problem. As illustrated in FIGS. 15 through 17, the two-pawl type wrench includes a handle 1xe2x80x2 and a head 11xe2x80x2 extended from the handle 1xe2x80x2. A drive member 2xe2x80x2 is rotatably received in the head 11xe2x80x2, a receptacle 12xe2x80x2 is defined in a web between the handle 1xe2x80x2 and the head 11xe2x80x2, and a spring-biased switch member 4xe2x80x2 is mounted in a cavity 13xe2x80x2 in the web. Two spaced pawls 3xe2x80x2 are received in the receptacle 12xe2x80x2 and are biased by two springs 6xe2x80x2, respectively. A threaded end cap 5xe2x80x2 is engaged with a threaded outer end 121xe2x80x2 of the receptacle 12xe2x80x2 to enclose the pawls 3xe2x80x2 and springs 6xe2x80x2. As illustrated in FIGS. 16 and 17, the switch member 4xe2x80x2 is turned to bias one of the pawls 3xe2x80x2 to engage teeth 31xe2x80x2 thereof with the drive member 2xe2x80x2 to thereby change the ratcheting direction of the wrench. However, it was found that the switch member 4xe2x80x2 cannot be reliably retained in place and thus tends to disengage from the cavity 13xe2x80x2. In addition, the pawl 3xe2x80x2 engaged with the drive member 2xe2x80x2 is not engaged with an inner longitudinal wall that defines the transverse through-hole and that faces the drive member 2xe2x80x2. As a result, the torque-bearing capacity of the wrench is poor. Furthermore, the outer pawl 3xe2x80x2 (FIGS. 16 and 17) tends to get stuck when the threaded end cap 5xe2x80x2 is mounted too close to the switch member 4xe2x80x2. On the other hand, if the threaded end cap 5xe2x80x2 is too far away from the switch member 4xe2x80x2, the pawl 3xe2x80x2 cannot be firmly engaged with the drive member 2xe2x80x2. Further, the threaded end cap 5xe2x80x2 tends to be disengaged from the web between the handle 1xe2x80x2 and the head 11xe2x80x2, as the former is in threading engagement with the threaded outer end 121xe2x80x2 of the receptacle 12xe2x80x2.
FIGS. 18 through 20 illustrate another conventional wrench having a substantially V-shape transverse through-hole 25xe2x80x2 in a web between a handle 20xe2x80x2 and a head 21xe2x80x2 thereof. The head 21xe2x80x2 includes a compartment in which a drive member 22xe2x80x2 is rotatably received. A spring-biased pawl 23xe2x80x2 is received in each limb of the V-shape transverse through-hole 25xe2x80x2. A switch member 30xe2x80x2 includes a stem 35xe2x80x2 pivotally received in a cavity 24xe2x80x2 in the web and a thumb-piece 32xe2x80x2 extending from the stem 35xe2x80x2 for manual operation, thereby switching the switch member 30xe2x80x2 between two positions corresponding to two opposite ratcheting directions of the wrench. The thumb piece 32xe2x80x2 of the switch member 30xe2x80x2 includes a downwardly facing receptacle 36xe2x80x2 (FIG. 20) for receiving a spring 37xe2x80x2 and a ball 38xe2x80x2 that is biased by the spring 37xe2x80x2 to be positioned in one of two positioning recesses 281xe2x80x2 (FIG. 19) in a sector-like recessed area 28xe2x80x2 (FIG. 18) of the web. The switch member 30xe2x80x2 may be retained in place reliably. However, a C-clip 33xe2x80x2 is required for mounting the switch member 30xe2x80x2 in place. In addition, processing of the sector-like recessed area 28xe2x80x2 in the web and the V-shape transverse through-hole 25xe2x80x2 is difficult. Mounting of the switch member 30xe2x80x2 as well as the pawl 23xe2x80x2 and associated springs 26xe2x80x2 and threaded end caps 27xe2x80x2 are troublesome and time-consuming. The sector-like recessed area 28xe2x80x2 in the web results in an increase in the overall thickness of the wrench, which limits application of the wrench in limited spaces.
U.S. Pat. No. 6,282,991 discloses a biasing arrangement for a pawl of a reversible ratchet-type wrench. However, the pawl protrudes beyond the handle during change in the ratcheting direction and thus adversely affects operation of the wrench in a limited space, as the protruded portion of the pawl tends to impinge on an object in the limited space.
It is an object of the present invention to provide an easy-to-operate and easy-to-assemble ratcheting-type wrench.
In accordance with a first aspect of the invention, a wrench comprises:
a handle comprising a first lateral side and a second lateral side opposite to the first lateral side;
a head extended from the handle, a web being defined between the handle and the head, the head including a compartment, the web including a transverse through-hole having an intermediate portion communicated with the compartment, the transverse through-hole extending from the first lateral side to the second lateral side of the handle, a cavity being defined in the web and communicated with the transverse through-hole;
a drive member rotatably mounted in the compartment of the head and including a plurality of teeth on an outer periphery thereof;
a switch member mounted in the cavity and rotatable relative to the handle between two positions corresponding to two opposite ratcheting directions of the handle; and
a pawl mounted in the transverse through-hole and slidable along a lengthwise direction of the transverse through-hole, with the pawl remaining in the transverse through-hole during operation, the pawl including a first lateral side facing the compartment and a second lateral side facing away from the compartment, the first lateral side of the pawl including a first toothed portion and a second toothed portion that are selectively engaged with the teeth of the drive member according to one of the positions of the switch member relative to the handle, a groove being defined in the second lateral side of the pawl and including a first corner and a second corner;
the handle including an upper side, the cavity including a vertical portion extending to the upper side of the handle, the switch member including a column rotatably received in the vertical portion of the cavity, the column having a transverse hole that faces the groove of the pawl;
a coil spring mounted in the transverse hole of the column and having an enlarged portion abutting against an outer periphery of the column and surrounding the transverse hole of the column; and
a pin having a first end received in the coil spring and a second end received in the groove of the pawl, the second end of the pin being biased by the coil spring to be selectively, securely engaged in one of the first corner and the second corner of the groove of the pawl that corresponds to said one of the positions of the switch member relative to the handle.
In accordance with a second aspect of the invention, a wrench comprises:
a handle comprising a first lateral side and a second lateral side opposite to the first lateral side;
a head extended from the handle, a web being defined between the handle and the head, the head including a compartment, the web including a transverse through-hole having an intermediate portion communicated with the compartment, the transverse through-hole extending from the first lateral side to the second lateral side of the handle, a cavity being defined in the web and communicated with the transverse through-hole;
a drive member rotatably mounted in the compartment of the head and including a plurality of teeth on an outer periphery thereof;
a switch member mounted in the cavity and rotatable relative to the handle between two positions corresponding to two opposite ratcheting directions of the handle; and
a pawl mounted in the transverse through-hole and slidable along a lengthwise direction of the transverse through-hole, with the pawl remaining in the transverse through-hole during operation, the pawl including a first lateral side facing the compartment and a second lateral side facing away from the compartment, the first lateral side of the pawl including a first toothed portion and a second toothed portion that are selectively engaged with the teeth of the drive member according to one of the positions of the switch member relative to the handle, a groove being defined in the second lateral side of the pawl and including a first corner and a second corner;
the handle including an upper side, the cavity including a vertical portion extending to the upper side of the handle, the switch member including a column rotatably received in the vertical portion of the cavity, the column having a transverse hole that faces the groove of the pawl;
an elastic element mounted in the transverse hole of the column and having an end abutting with an inner peripheral wall defining the vertical portion of the cavity;
a pin having a first end that is received in the transverse hole of the column and that has a receptacle for receiving another end of the elastic element, the pin further having a second end received in the groove of the pawl, the second end of the pin being biased by the elastic element to be selectively, securely engaged in one of the first corner and the second corner of the groove of the pawl that corresponds to said one of the positions of the switch member relative to the handle.